Apparatus for developing photographic films

ABSTRACT

One or more developing drums having spaced opposite ends are mounted for rotation in a housing and a supply supplies liquid developer to the interior of these drums. Raising arrangement utilizing eccentric cams or the like is provided for alternately raising or lowering one end of each drum at predetermined time intervals and through a predetermined distance to thereby cause longitudinally traveling waves of the developer in the drums.

[15] 3,682,080 [4 1 Aug. 8, 1972 United States Patent Men [541 APPARATUSFOR DEVELOPING 12/1966 Hallquist........t..............95/99 95/933,292,519 2,947,236 8/1960 Siege].....................

Primary Examiner-Samuel S. Matthews Assistant Examiner-Richard M. SheerAttomey-Mibhael S. Striker 791 l Oberelchingen, Germany Nov. 6, 1970[22] Filed:

ABSTRACT.

[2!] Appl. No.: 87,493

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m 1 ma F V. M d O UNITED STATES PATENTS 12/1970 Carrie.......

BACKGROUND OF THE INVENTION The present invention relates generally tophotographic apparatus, and more particularly to apparatus fordeveloping photographic films. 1

The term photographic film as employed herein is intended to refergenerally to all photographic film materials in their broadest form.Obviously this includes sheet material-type films, strip-shaped filmsand the like. The present invention is particularly ad vantageous,however, with respect to sheet-material shaped films. I

It is already known from the art to provide an apparatus for developingphotographic films of the sheetmaterial type in which developer drumsare rotated and accommodate both the film to be developed and a liquiddeveloper which is needed to develop the film and which is to be broughtinto uniform contact therewith. A different approach known from the artprovides for a housing which is sealed against the entry of light and inwhich there is mounted an elongated tray pivotable about itslongitudinal axis. A rotatable drum, on which the photographic materialto be developed is mounted, rotates and dips the photographic materialinto the developer accommodated into the tray. According to a preferredembodiment of this latter prior art construction the drum should beconfigurated as a paddle wheel with the film material to be developedbeing supported on this paddle wheel.

These constructions known from the prior art are by no meansinoperative. However, it has been found that p it is impossible toprovide-by utilizing them adequate developing of modern photographicmaterials, the reason being that such modern photographic materials arehighly sensitive to flaws in the developing process. In particular ithas been found that with these known prior art constructions it is verydiificult to so wash the photographic materials with the developerliquid that the materials are uniformly treated with the liquid in amanner avoidingthe formation of schlieren and of developingirregularities. The term schlieren designates a phenomenon in whichstreaks develop and is known to those skilled in the art.

SUMMARY OF THE INVENTION tively simple in its construction but highlyreliable and efficient in its operation.

A concomitant object of the present invention is to provide such anapparatus which is simple to operate.

In pursuance of the above objects, and others which I Supply means isprovided for supplying liquid developer to the interior of the drum andraising means is provided for raising of the ends of the drum atpredetermined time intervals and through a predetermined distance.

In this manner I assure that at these predetermined time intervals thedeveloped liquid will travel through the drum in the form of alongitudinally advancing (with respect to the elongation of the drum)wave which will uniformly wash over the film material contents of thedrum. When the wave reaches the opposite end it is reflected therefromand travels back towards the first or one end where it originated andwhich in the meantime has been allowed to descend to its startingposition. Now the one end is raised again and the travel of thedeveloper liquid is renewed. Of course, the intervals at which the oneend of the drum is raised, and the distance through which it is raised,are synchronized with the travel of the wave so as not to interfere withthe same.

When the film materials, particularly sheet-like film materials, areaccommodated in the interior of such a developer drum which rotates andis raised in the manner just discussed, they no longer simply in effectslide into the more or less stationary developing liquid, but insteadare subjected to the washing action of the developer liquid waves whichtravel to and fro between the opposite ends of the drum. This assures aconstant uniform contacting of the film material with the developingliquid.

Various different ways are conceivable and suitable for raising thedrum. According to a particularly simple concept of the invention Iprovide for an excenter drive utilizing an excentrically mountedrotating cam which is located between one end of the drum and soarranged that as the cam rotates, it contacts the exterior of the drumand lifts this one end thereof upwardly by the desired predetermineddistance. This is a mechanically rather simple construction which is yethighly reliable and in which the distance through which the drum israised, and the time intervals at which it is raised, can

will become apparent hereafter, one feature of the in- Y vention recitesin an apparatus for developing-photographic film which, briefly stated,comprises a housing, at least one developing drum in the housing andhaving spaced opposite ends, and drive means mounting the drum forrotation about a substantially horizontal axis.

' mental to the desired formation of the wave be varied by exchangingthe cam for another one. The opposite end of the drum may be pivotablymounted on the support of the apparatus, for instance a supporting tableor the like.

It is also advantageous according to a further conceptv of the inventionto construct the drum of two parts, a main part and a terminal partwhich is located at that'end of the drum where the developer liquid isto be poured out when it is spent. The terminal part tapers conically indirection away from the main part and intermediate the two an annularmember may be accommodated in the interior of the drum and be providedinto its outer edge with inwardly extending recesses. The conical partfacilitates pouring-out of developer liquid when the latter is to bereplaced with new liquid. On the other hand, its internal taper would bedetrito and fro in the area of the drum, because the taper of the innerwall surface of the conical portion would not properly reflect the waveback in the opposite axial direction. This difficulty is overcome byproviding the annular element which provides for such reflection butwhich, due to the recesses in its outer periphery, does not hinderpouring-out of the developer liquid when such is desired.

travelling It is advantageous but not necessary that the inner diameterof the central aperture in the annular element be so selected that asthe wave of developer liquid is reflected from the annular element, theliquid will not pour through the central aperture. Of course, to do thisit is necessary to take into consideration not only the diameter of thecentral aperture but also other factors such as the distance throughwhich the one end of the drum is raised, the periodicity at which it israised and the quantity of developer liquid which is to be accommodatedin the drum. However, a simple experimentation will readily enableanyone skilled in the art to determine these factors and theirco-relationship. In a similar manner the optimum number, location andconfiguration of the recesses in the outer periphery of the annularmember can be empirically determined.

It is also advantageous to have the one end of the drum initially openwith a removable ring of resilient material, for instance an elastomericmaterial, placed over it in fluid-tight relationship with thecircumferential wall of the drum. The ring again has a central aperturewhich is selected in such a manner that the wave of developer liquid isreflected from it the ring but that no developer liquid will pourthrough the central aperture.

The drum or drums may be supported on rotating drive rollers, andaccording to the invention it is advantageous if these drive rollers aredriven by a prime mover, usually an electromotor, which permits them tobe intermittently driven rather than continuously. This is a furthermeasure which quite substantially improves the contact between the filmmaterial and the developer liquid.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION THE DRAWING FIG. 1 is a partially sectioned end viewof an apparatus according to the present invention;

FIG. 2 is a cross-section through one of the developer drums of theapparatus shown in FIG. 1, looking from the left towards the right inFIG. 3;

FIG. 3 is a partial longitudinal section through the apparatus of FIG.1; and

FIG. 4 is a longitudinal section through the developer drum in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing indetail it is firstly pointed out that the single exemplary embodimentshown in FIG. 1 is just that, namely an example, and that variousmodifications can and are intended to be incorporated within the contextof the present invention.

FIGS. 1 and 3 show that the apparatus according to bodirnent, with amounting arrangement including support or table 2 which rests on legs oruprights 1. At one axial end of the table 2 there are provided twotransversely spaced bearing brackets 8 each of which carries a shaft 7.Mounted turnably on each of the shafts 7 is a lug 6 which in turn issecured to the housing 3 of the apparatus.

The lugs 6 are secured to the housing 3 adjacent one end of theelongated housing, and in the region of the opposite end of the housing3 there is provided raising means for alternately raising and loweringone end of the housing and thereby of the developer drum 4 accommodatedtherein. This raising means is here in form of an excentric cam disc 11mounted on a shaft 9 which in turn is joumalled in the bearing brackets10 (compare FIGS. 1 and 3) and driven in rotation by the geared motor 12which can be of any of the various well-known prior art constructions.Evidently, as the shaft 9 is driven in rotation and consequently theexcentric cam disc 11 is similarly rotated, it being understood that thecam disc 11 is fast with the shaft 9,

the housing 3 is periodically raised and lowered by a distance which,together with the periodicity, depends upon the eccentricity of the camdisc 1 1. When the disc is circular as illustrated, the raising andlowering movement is sinusoidal as related to time, but it will beappreciated that any other configuration can be obtained by diflerentlyconfigurating the cam disc 1 l.

I have illustrated an apparatus in which the housing 3 accommodates twoelongated developer drums 4, but it will be understood that theinvention is similarly applicable even if there is a single one of thesedrums 4 providedor if there are more than two of them. The drums 4 areeach mounted for rotation on the drive rollers 5 which in turn areconnected with a drive shaft 24 joumaled in the illustrated bearingbrackets 25 and being rotated intermittently by the geared drive motor'23. Motors for this purpose are known and need not be further describedbecause in themselves their construction does not form a part of thepresent invention.

It is pointed out, however, that a separating wall in the housing 3separates that portion thereof which accommodates the drums 4, from aseparate chamber 26 in which the motor 23 is located. At the same time,the chamber 26 also accommodates a container 21 constituting a part ofsupply means which supplies liquid developer to the interior of thedrums 4. This is accommplished by having the liquid developer (shown inthe receptacle 21 in FIG. 3) pass through an illustrated conduit inwhich an illustrated valve in interposed (neither identified withseparate reference numerals) into the interior of the respective drums4.

The drums 4 are open at the ends facing the chamber 26 in theillustrated embodiment, and are provided with end caps which are ofannular configuration and identified with reference numeral 18. Theyconsist of a resilient material, for instance an elastomeric material asillustrated, and are provided with a central aperture 27 whose diameteris so selected that the waves of developer liquid travellinglongitudinally of the drums 4 will not pour through the central aperture27.

In the region of the opposite axial end each of the drums 4 in theillustrated embodiment is provided with a conically converging ortapering terminal portion 16 the present invention is provided, in theillustrated emthrough whose opening the developer liquid is to be pouredout when it is used up or spent. This is done when the apparatus is notin operation, that is when the drums 4 do not rotate, at which time theleft-hand end of the respective drum 4 can be raised (for instance bydisconnecting it from the end cap 18) so that the developer liquid willpour out through the opening of the terminal portion 16. At this timethe drum 4 is supported by the bearing bracket 20 illustrated in FIG. 3.

As FIGS. 2-4 show most clearly, I also provide at the juncture betweenthe main portion of the respective drum 4 (that is the cylindricalportion) and the convergent terminal portion 16, an annular member 17having a central aperture 28 corresponding approximately to the centralaperture 27 and preventing due to the diameter selected for it,pouring-out of the travelling wave of developer liquid. The purpose ofelement 17 is, of course, to reflect the wave as it reaches the element17, because the convergent inner surface of the sectional portion 16would not provide for a proper reflection. As shown particularly in FIG.2, the element 17 is provided in its outer periphery with inwardlyextending recesses, cutouts or the like which are identified withreference numeral 19 and which, while they do not prevent reflection ofthe traveling wave of developer liquid, make it possible to readily pourout the developer liquid when the drum is raised in the manner discussedbefore, that is by raising it at the left-hand end rather than at theright-hand end (as in FIG. 3) where the raising is accomplished with theeccentric cam disc 11 and not for the purpose of pouring the liquid outbut only in order to produce a traveling wave of liquid.

The drums are each provided in their interior with supports 15 on whichthe film material to be developed is supported so it can slidecircurnferentially of the drums as they rotate.

It will be appreciated that by resorting to my invention a much-improvedcontacting of the film material with the developer liquid is obtained,and that this contacting is not to any appreciable extent diminished insuch embodiments where I provide the element 17 with the cutouts orapertures 19 therein.

It will be understood that each of the elements described above, or twoor more together, may also I find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in anapparatus for developing photographic film, it is not intended to belimited to the details shown, since various modifications and structuralchanges may be made without departing in any way from the spirit of thepresent invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations-should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. In an apparatus for developing photographic films, in combination atleast one developing drum having spaced opposed ends and being adaptedto contain therein photographic films and developing fluid; ti siinii ioil fi ix isf diii fiffihifii said drum; and raising means cooperatingwith said drive means for affecting sequential raising and lowering oneof said ends of said drum during rotation of the latter for creatingtherein longitudinally travelingwaves of developing fluid in asubstantially axial direction of said drum to improve development ofphotographic films contained therein.

2. In an apparatus as defined in claim 1, wherein said raising meanscomprises excenter drive means beneath and operative for raising saidone end.

3. In an apparatus as defined in claim 1, said raising means comprisingeccentric cam means.

4. In an apparatus as defined in claim 1, said drive means comprisingdrive rollers supporting said drum and operative for rotating the sameabout said axis.

5. In an apparatus as defined in claim 1; and further comprisingmounting means mounting said drum in the region of the other of saidends for pivotal displacement about an other substantially horizontalaxis extending transversely to the first-mentioned axis.

6. In an apparatus as defined in claim 5; further comprising a support;and wherein said mounting means mounts said drum on said support. a

7. In an apparatus as defined in claim 1, said drum having a mainportion, and a terminal portion tapering conically away from said mainportion and towards said one end, said terminal portion having an outletopening for developing fluid in the region of said one end; and furthercomprising an annular member accommodated in said drum at the junctureof said portions and being provided with circurnferentially spacedrecesses for facilitating movement of developing fluid between saidportions.

8. In an apparatus as defined in claim 7, said drum accommodating apredetermined quantity of developing fluid and said annular memberhaving a central aperture whose diameter is so selected with referenceto said quantity and said distance that waves of developing fluidresulting from said raising and travelling longitudinally of said drum,are prevented from passing through said central aperture.

9. In an apparatus as defined in claim 1, said drum being open at saidone end; and further comprising a cap of resilient material overlyingand substantially closing said other end in removable relationshiptherewith.

10. In apparatus as defined in claim 1, said drive means comprisingdrive rollers supporting and rotating said drum, and motor means forintermittently rotating said drive rollers.

1. In an apparatus for developing photographic films, in combination atleast one developing drum having spaced opposed ends and being adaptedto contain therein photographic films and developing fluid; mountingmeans mounting said drum for rotation about a substantially horizontalaxis; drive means for rotating said drum; and raising means cooperatingwith said drive means for affecting sequential raising and lowering oneof said ends of said drum during rotation of the latter for creatingtherein longitudinally traveling waves of developing fluid in asubstantially axial direction of said drum to improve development ofphotographic films contained therein.
 2. In an apparatus as defined inclaim 1, wherein said raising means comprises excenter drive meansbeneath and operative for raising said one end.
 3. In an apparatus asdefined in claim 1, said raising means comprising eccentric cam means.4. In an apparatus as defined in claim 1, said drive means comprisingdrive rollers supporting said drum and operative for rotating the sameabout said axis.
 5. In an apparatus as defined in claim 1; and furthercomprising mounting means mounting said drum in the region of the otherof said ends for pivotal displacement about an other substantiallyhorizontal axis extending transversely to the first-mentioned axis. 6.In an apparatus as defined in claim 5; further comprising a support; andwherein said mounting means mounts said drum on said support.
 7. In anapparatus as defined in claim 1, said drum having a main portion, and aterminal portion tapering conically away from said main portion andtowards said one end, said terminal portion having an outlet opening fordeveloping fluid in the region of said one end; and further comprisingan annular member accommodated in said drum at the juncture of saidportions and being provided with circumferentially spaced recesses forfacilitating movement of developing fluid between said portions.
 8. Inan apparatus as defined in claim 7, said drum accommodating apredetermined quantity of developing fluid and said annular memberhaving a central aperture whose diameter is so selected with referenceto said quantity and said distance that waves of developing fluidresulting from said raising and travelling longitudinally of said drum,are prevented from passing through said central aperture.
 9. In anapparatus as defined in claim 1, said drum being open at said one end;and further comprising a cap of resilient material overlying andsubstantially closing said other end in removable relationshiptherewith.
 10. In apparatus as defined in claim 1, said drive meanscomprising drive rollers supporting and rotating said drum, and motormeans for intermittently rotating said drive rollers.